/*
  将下面异步代码使用 Promise 的方法改进
  尽量用看上去像同步代码的方式
  setTimeout(function () {
    var a = 'hello'
    setTimeout(function () {
      var b = 'lagou'
      setTimeout(function () {
        var c = 'I ♥ U'
        console.log(a + b +c)
      }, 10)
    }, 10)
  }, 10)
*/

const promiseA = new Promise((resolve) => {
  setTimeout(() => {
    var a = "hello";
    resolve(a);
  }, 10);
});

const promiseB = new Promise((resolve) => {
  setTimeout(() => {
    var b = "lagou";
    resolve(b);
  }, 10);
});

const promiseC = new Promise((resolve) => {
  setTimeout(() => {
    var c = "I ♥ U";
    resolve(c);
  }, 10);
});

async function main() {
  const resA = await promiseA;
  const resB = await promiseB;
  const resC = await promiseC;
  console.log(resA + resB + resC);
}

main();
